Extractor for boiler tube expanders



' y 1964 R. J. RIDINGS 3,

EXTRACTOR FOR BOILER TUBE EXPANDERS Filed July 17, 1961 7-7,- Z 7/5... E

IN V EN TOR. POBERTJ. RID/N68 PATENT AGE/VT United States Patent C) 3,133,342 EXTRACTOR FOR BOILER TUBE EXPANDERS Robert J. Ridings, 251 Dana St., Mountain View, Calif. Filed July 17, 1961, Ser. No. 124,618 r 2 Claims. (Cl. 29259) The present invention generally relates to tools and more particularly to a specific form of tool that functions as an extractor for boiler tube expanders.

In either'the initial installation or replacement of the heat exchange tubes in a boiler, it is accepted practice to secure the end of each boiler tube to the mounting wall or tube sheet, as it is commonly referred to, by an expansion process. More particularly, the boiler tube is inserted to the appropriate position, and a boiler tube expander is then inserted into the end of the tube and is actuated to exert an outwardly directed force on the tube so that its exterior is pressed into tight engagement with the surrounding tube sheet. Such actuation is normally accomplished by the insertion of a tapered mandrel into a series of surrounding rolls which, in turn, engage and force outwardly the boiler tube. The expansion force must be considerable in many instances since in use of the installed tubes, boiler and steam pressures in excess of 2000 pounds per square inch are frequently encountered; and the pressed fit of the boiler tubes in the tube sheet must be able to Withstand such pressures without leakage. Since these relatively great expansion forces must be applied during the instllation of a boiler tube, not too infrequently the boiler tube expander breaks during the 6 installation. Most commonly, such breakage specifically constitutes a shearing of the tapered mandrel and the expander itself can accordingly be withdrawn only with difliculty since it is tightly lodged within the boiler tube. In instances known to me, several days have been required to eifect withdrawal of a broken tube expander, and the boiler tube, itself, was damaged during the withdrawal operation.

Accordingly, it is a general object of the present invention to provide an extractor which can be utilized for extracting a broken boiler tube expander quickly, easily, and Without damage to the expander or the boiler tube itself.

Specifically, it is a feature of the invention to provide an extractor for a boiler tube expander that can be easily placed in extracting position and can then be rapidly and easily actuated to effect the extraction.

Additionally, it is a feature of the invention to provide 7 an extractor for a boiler tube expander that includes gripping jaws arranged to be held firmly in expandergripping engagement during the application of the relatively great extraction forces required.

A related feature is the provision of an extractor for a boiler tube expander that is substantially self-aligning wherefore the extraction forces are applied substantially in axial alignment with the disposition of the expander.

Another important feature of the invention is the provision of an extractor which is of simple but rugged construction so that it has substantial longevity in its usefulness in spite of the great magnitude of the forces encounted.

Yet an additional feature is the provision of an extractor for boiler tube expanders that can readily accommodate expanders of slightly variant design, as encountered in common industrial applications.

These as well as additional objects and features of the invention will become more apparent from a perusal of the following description of the structure illustrated in the accompanying drawing wherein:

FIG. 1 is a side elevational view of an extractor embodying the present invention applied to a broken boiler tube expander lodged within a boiler tube,

FIG. 2 is a central'longitudinal section taken along line 2-2 of FIG. 1 and illustrating details of the extractor and expander construction, and a FIG. 3 is a transverse sectional view taken substantially along line 3-3 of FIG. 2 and illustrating additional details of construction of the extractor and its engagement with the boiler tube expander.

With initial reference to FIGS. 1 and 2, a fragmentary portion of a boiler is illustrated merely to provide the general locus of the invention. As shown best in FIG. 2, the end of a boiler tube 10 has been expanded into the surrounding tube sheet or wall 12 by means of actuation of a boiler tube expander, generally indicated at 14. Such expander 14 includes a generally cylindrical body 16 that projects into the boiler tube 10 and carries a plurality of rolls 18 in circumferentially spaced relation and having an interior axial taper so that insertion of a mandrel 20 of corresponding external taper forces the rolls into the expanding engagement with the boiler tube 10 to press the same into engagement with the surrounding tube sheet 12. As clearly illustrated in FIG. 2, the mandrel 20 has been broken, as indicated at 20a, wherefore its withdrawal in the conventional fashion is prohibited and the expansion rolls 18 are accordingly wedged into tightly pressed engagement with the inner surface of the expanded boiler tube 10 so that the entire expander 14 is tightly lodged in the position illustrated in FIG. 2.

In accordance with the present invention, the extractor, generally indicated at 30, is arranged to establish gripping engagement with a shoulder formed on the body 16 of the expander exteriorly of the boiler tube 10. More particularly, such gripping engagement is achieved by a pair of gripping jaws 32, each of which constitutes a semi-cylindrical section having an inturned flange 32a at its lower end as viewed in FIG. 2, so as to be adapted for engagement with the described shoulder on the expander body 16. At the upper ends of the semi-cylindrical gripping jaws 32, inturned annular flanges 32b are also formed and are adapted to overlie a pressure plate 34 secured to the lower end of an actuating screw 36. Such actuating screw 36 extends upwardly through a nut 38 that is mounted on an annular flange 40 rigidly secured at its periphery on a cylindrical sleeve 42 whose dimensions are such as to confine closely the described semicylindrical gripping jaws 32 and hold the same in engagement with the shoulder of the expander body 16, as illustrated clearly in FIG. 2, yet permit sliding movement of the gripping jaws within the interior of the sleeve. As shown, the lower extremity of the jaw-encompassing sleeve 42 engages the surface of the tube sheet 12 wherefore it will be seen that if the actuating screw 36 is rotated by application of a wrenchto the upper squared end thereof, the pressure plate will move upwardly against the upper flanges 32b of the gripping jaws and force will, in turn, be transmitted through the inturned flanges 32a at the lower end of the gripping jaws 32 and against the shoulder of the expander 14 to effect upward movement of the latter. A reactive force is obviously transmitted through the sleeve 42 to the tube sheet 12 against which it bears at its lower end.

Preferably, as illustrated, the cylindrical sleeve 42 is angularly cut away at opposite sides adjacent its lower end so that substantially point contact is established with the tube sheet 12 to thus allow the sleeve and the remainder of the structure of the extractor mounted thereon to pivot slightly and thus automatically align itself axially with the expander 14 during the exertion of the extracting force. Furthermore, as shown best in FIG. 3 several notches 44 are formed in the gripping flanges 32a to accommodate the belling rolls found on some expander units.

In order to initially apply the extractor 30 to a broken boiler tube expander 14, the sleeve 42 is retracted upwardly from the position illustrated in FIGS. 1 and 2 sufficiently so that the gripping jaws 32 are freed for placement around the expander. Thereafter, thesleeve 42 is moved downwardly into jaw encompassing relationship, as illustrated, and force may be applied to the upper end of the actuating screw 36 to effect withdrawal of the expander in the manner previously described.

Obviously, various modifications and/ or alteration can be made in the described structure without departing from the spirit of the invention; and accordingly, the foregoing description of one embodiment of the invention is to be considered as purely exemplary and not in a limiting sense; and the actual scope of the invention is to be indicated by reference to the appended claims.

What is claimed is:

1. An extractor for a boiler tube expander having an exterior shoulder at its outer, exposed end which comprises a plurality of independent gripping jaws adapted for axial abutting engagement with the shoulder on the boiler tube expander, means for encompassing and holding said gripping jaws in such gripping engagement, and means for applying an axial force between said gripping jaws and said jaw-holding means to exert an axial pull on the boiler tube expander, said jaw-holding means including a cylindrical sleeve angularly cut away for establishing pivotal point contact with a supporting structure.

2. An extractor for a boiler tube expander according to claim 1 wherein said force applying means includes an actuating screw connected between said gripping jaws and said encompassing sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,357,698 Fessenden Nov. 2, 1920 1,387,895 McBride Aug. 16, 1921 1,445,001 Campbell Feb. 13, 1923 2,467,982 Maris Apr. 19, 1949 FOREIGN PATENTS 1,830 Great Britain May 21, 1914 707,986 France July 17, 1931 

1. AN EXTRACTOR FOR A BOILER TUBE EXPANDER HAVING AN EXTERIOR SHOULDER AT ITS OUTER, EXPOSED END WHICH COMPRISES A PLURALITY OF INDEPENDENT GRIPPING JAWS ADAPTED FOR AXIAL ABUTTING ENGAGEMENT WITH THE SHOULDER ON THE BOILER TUBE EXPANDER, MEANS FOR ENCOMPASSING AND HOLDING SAID GRIPPING JAWS IN SUCH GRIPPING ENGAGEMENT, AND MEANS FOR APPLYING AN AXIAL FORCE BETWEEN SAID GRIPPING JAWS AND SAID JAW-HOLDING MEANS TO EXERT AN AXIAL PULL ON THE BOILER TUBE EXPANDER, SAID JAW-HOLDING MEANS INCLUDING A CYLINDRICAL SLEEVE ANGULARLY CUT AWAY FOR ESTABLISHING PIVOTAL POINT CONTACT WITH A SUPPORTING STRUCTURE. 